Filters








131 Hits in 7.6 sec

Including Spatial Information in Nonlinear Inversion MR Elastography Using Soft Prior Regularization

Matthew McGarry, Curtis L. Johnson, Bradley P. Sutton, Elijah Ew Van Houten, John G. Georgiadis, John B. Weaver, Keith D. Paulsen
2013 IEEE Transactions on Medical Imaging  
This paper implements and evaluates soft prior regularization (SPR), through which homogeneity in predefined spatial regions is enforced by a penalty term in a nonlinear inversion strategy.  ...  Despite its availability, few attempts to incorporate prior spatial information in the MRE reconstruction process have been reported.  ...  One type of regularization not yet explored by the majority of MRE inversions is incorporation of spatial priors in the material property estimation process.  ... 
doi:10.1109/tmi.2013.2268978 pmid:23797239 pmcid:PMC4107367 fatcat:r7rqfa7txfbb3bahxcgpyewcaa

Model-based elastography: a survey of approaches to the inverse elasticity problem

M M Doyley
2012 Physics in Medicine and Biology  
This paper reviews current approaches to elastography in three areas-quasi-static, harmonic and transient-and describes inversion schemes for each elastographic imaging approach.  ...  Wang et al -Silicone phantom validation of breast cancer tumor detection using nominal stiffness identification in digital imaging elasto-tomography (DIET) Cong Zhou et al -A Modified 2D Multiresolution  ...  (b) Spatial priors. In addition to regularization, other methods could transform the ill-posed inverse elasticity problem to a well-posed one.  ... 
doi:10.1088/0031-9155/57/3/r35 pmid:22222839 pmcid:PMC3374584 fatcat:ozo27uu2ynfktcoyk6j63jkn4i

Spatially-Resolved Hydraulic Conductivity Estimation Via Poroelastic Magnetic Resonance Elastography

Adam J. Pattison, Matthew McGarry, John B. Weaver, Keith D. Paulsen
2014 IEEE Transactions on Medical Imaging  
Material property contrast was recovered experimentally in three different tofu phantoms and the accuracy was improved through soft-prior regularization.  ...  Estimating spatially-varying hydraulic conductivity would likely improve model accuracy and provide new image information related to a tissue's interstitial fluid compartment.  ...  We also incorporated the option to include soft-prior regularization following the methods outlined in detail elsewhere [33] in which individual property parameters (i.e., nodes in the FEM mesh) are  ... 
doi:10.1109/tmi.2014.2311456 pmid:24771571 pmcid:PMC4510837 fatcat:lok36jspqjfwbijguieovcynta

Modality Independent Elastography (MIE): A New Approach to Elasticity Imaging

C.W. Washington, M.I. Miga
2004 IEEE Transactions on Medical Imaging  
Index Terms-Breast cancer, elasticity, elastography, image registration, image similarity, inverse problem, mutual information, soft tissue, stiffness, Young's modulus.  ...  The modality independent elastography (MIE) method combines a nonlinear optimization framework, computer models of soft-tissue deformation, and standard measures of image similarity to reconstruct elastic  ...  Fitzpatrick at Vanderbilt University for conducting MR simulations alluded to in Section IV of this paper.  ... 
doi:10.1109/tmi.2004.830532 pmid:15377121 fatcat:hlpqjnq7mngc7bh5grxfixpoiq

Finite deformation elastography of articular cartilage and biomaterials based on imaging and topology optimization

Luyao Cai, Eric A. Nauman, Claus B. W. Pedersen, Corey P. Neu
2020 Scientific Reports  
optimization routine to investigate stiffness heterogeneity, including spatial gradients and inclusions.  ...  Conventional elastography quantifies stiffness in soft (e.g. brain, liver) tissue, but robust quantification in stiff (e.g. musculoskeletal) tissues is challenging due to dissipation of high frequency  ...  Acknowledgements This work was supported in part by National Institutes of Health (NIH) grants R01 AR063712 and R21 AR066230, and National Science Foundation (NSF) grant CMMI CAREER 1349735.  ... 
doi:10.1038/s41598-020-64723-9 pmid:32409711 fatcat:xnnjlc7fyje4ldieyn7faj76c4

A bayesian method for accelerated magnetic resonance elastography of the liver

Christopher Ebersole, Rizwan Ahmad, Adam V. Rich, Lee C. Potter, Huiming Dong, Arunark Kolipaka
2018 Magnetic Resonance in Medicine  
BEAM is validated using iii retrospectively downsampled phantom data and prospectively downsampled in vivo liver data (n = 86).  ...  The proposed method, called Bayesian method for magnetic resonance Elastography using Approximate Message passing (BEAM) utilizes a combination of several features to accelerate reconstruction.  ...  On the other hand, the factors in the prior, such as ( ), ( ), and ( 0 )provide a regularization effect in image reconstruction.  ... 
doi:10.1002/mrm.27083 pmid:29334131 fatcat:igqrhp7h4faqzeg7knfmopjoo4

Contrast-Enhanced Quantitative Intravascular Elastography: The Impact of Microvasculature on Model-Based Elastography

Steven Huntzicker, Himanshu Shekhar, Marvin M. Doyley
2016 Ultrasound in Medicine and Biology  
Model-based intravascular ultrasound elastography visualizes the stress distribution within vascular tissue -information that clinicians could use to predict the propensity of atherosclerotic plaque rupture  ...  In simulations diameters of 200,400, and 800 microns were used, where the latter diameter represented a cluster of microvessels. In phantoms, we used a microvessel with diameter of 750 microns.  ...  ) by incorporating geometric information (spatial priors) in the image reconstruction process (Doyley, et al. 2006 , Huntzicker, et al. 2014 .  ... 
doi:10.1016/j.ultrasmedbio.2015.12.024 pmid:26924697 pmcid:PMC4811726 fatcat:yondgel2n5ghrecnom22hbzg5q

Why Are Viscosity and Nonlinearity Bound to Make an Impact in Clinical Elastographic Diagnosis?

Guillermo Rus, Inas H. Faris, Jorge Torres, Antonio Callejas, Juan Melchor
2020 Sensors  
First, by providing an insight into the classic role of soft tissue microstructure in linear elasticity; secondly, by understanding how viscosity and nonlinearity could enhance the current diagnosis in  ...  The adoption of multiscale approaches by the biomechanical community has caused a major improvement in quality in the mechanical characterization of soft tissues.  ...  Technique Soft Tissue Study Objective Method Reference SDUV Liver in vivo porcine Regular characterization Dispersion curve Voigt model Chen et al. [98] Liver in vivo Regular characterization  ... 
doi:10.3390/s20082379 pmid:32331295 pmcid:PMC7219338 fatcat:xpqhc4vujvcxtd76xasuchg5je

Viscoelasticity Imaging of Biological Tissues and Single Cells Using Shear Wave Propagation

Hongliang Li, Guillaume Flé, Manish Bhatt, Zhen Qu, Sajad Ghazavi, Ladan Yazdani, Guillaume Bosio, Iman Rafati, Guy Cloutier
2021 Frontiers in Physics  
Changes in biomechanical properties of biological soft tissues are often associated with physiological dysfunctions.  ...  Finally, current limitations and future directions in shear wave elastography are presented.  ...  Uniqueness of Poroelastic and Viscoelastic Nonlinear Inversion MR Elastography at Low Frequencies.  ... 
doi:10.3389/fphy.2021.666192 fatcat:qvn4pciaxbdbfhynp4spzszrii

Phantom evaluations of nonlinear inversion MR elastography

Ligin M Solamen, Matthew D McGarry, Likun Tan, John B Weaver, Keith D Paulsen
2018 Physics in Medicine and Biology  
Reconstruction parameters identical to those used in recent in vivo MRE studies of mechanical property variations in small brain structures were applied.  ...  This study evaluated non-linear inversion MRE (NLI-MRE) based on viscoelastic governing equations to determine its sensitivity to small, low contrast inclusions and interface changes in shear storage modulus  ...  Although NLI-MRE has the capability to employ other regularization techniques including soft prior regularization, total variation minimization and Tikhonov regularization, they were not used in this study  ... 
doi:10.1088/1361-6560/aacb08 pmid:29877194 pmcid:PMC6095192 fatcat:bccn32gvhvdg5dpnmqkfdvxp2i

Seventh International Conference

Colin Murray Parkes, Rosie Dalzell, Mike Pearson, Martin Newman
2005 Bereavement Care  
data used in this study.  ...  Li, "Elastography: a quantitative method for imaging the Acknowledgements: This study was partially supported by the French National Department of Research and Education.  ...  Gel dosimeters are being used for such measurements, where dose information can be obtained in spatial 3D volume with high spatial resolution.  ... 
doi:10.1080/02682620508657640 fatcat:hwoqd64zz5b6bkhpyteeazib5u

Application of multi-resolution modality independent elastography for detection of multiple anomalous objects

Jao J. Ou, Stephanie L. Barnes, Michael I. Miga, Armando Manduca, Amir A. Amini
2006 Medical Imaging 2006: Physiology, Function, and Structure from Medical Images  
This work extends a recently realized inverse problem technique of extracting soft tissue elasticity information via nonrigid model-based image registration.  ...  The algorithm uses the elastic properties of the tissue in a biomechanical model to achieve maximal similarity between image data acquired under different states of loading.  ...  This work was supported in part by the Whitaker Foundation Young Investigator Award and the Congressionally Directed Medical Research Program BCRP Predoctoral Traineeship Award.  ... 
doi:10.1117/12.652345 fatcat:srjnmuqslvc5rheh3dpxkypuye

Imaging the elastic properties of tissue: the 20 year perspective

K J Parker, M M Doyley, D J Rubens
2010 Physics in Medicine and Biology  
of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro Circulation 102 617-23 Dickinson R J and Hill C R 1982 Measurement of soft tissue motions  ...  Symp. (20-23 Sep 2009, Rome, Italy) pp 519-22 Castéra L, Forns X and Alberti A 2008 Non-invasive evaluation of liver fibrosis using transient elastography J.  ...  Compression elastography Introduced in 1991 by Ophir et al (1991) compression elastography utilizes a comparison of ultrasound B-scan RF information from tissue before and after a modest compression.  ... 
doi:10.1088/0031-9155/56/1/r01 pmid:21119234 fatcat:d47jirqjnjf3ln5blhkxwfyddy

Imaging the elastic properties of tissue: the 20 year perspective

K J Parker, M M Doyley, D J Rubens
2010 Physics in Medicine and Biology  
of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro Circulation 102 617-23 Dickinson R J and Hill C R 1982 Measurement of soft tissue motions  ...  Symp. (20-23 Sep 2009, Rome, Italy) pp 519-22 Castéra L, Forns X and Alberti A 2008 Non-invasive evaluation of liver fibrosis using transient elastography J.  ...  Compression elastography Introduced in 1991 by Ophir et al (1991) compression elastography utilizes a comparison of ultrasound B-scan RF information from tissue before and after a modest compression.  ... 
doi:10.1088/0031-9155/56/2/513 fatcat:3tr654m5l5e7vbuo23lgw5ww24

Imaging of the elastic properties of tissue—A review

L. Gao, K.J. Parker, R.M. Lerner, S.F. Levinson
1996 Ultrasound in Medicine and Biology  
Recently, a number of methods have been developed that make it possible to image the elastic properties of soft tissues.  ...  In this paper, we survey some of the previous work done in the related field of biomechanics, and we review measurement techniques from the 1950s to the 1980s.  ...  Rubens in preparing the manuscript.  ... 
doi:10.1016/s0301-5629(96)00120-2 pmid:9004420 fatcat:5ond4q7upzbtzkqlss7a4tenje
« Previous Showing results 1 — 15 out of 131 results